Arrows are draw length and weight specific. Bow shop will install the D-loop then using a measuring device have you draw it several times to determine your correct draw length then you can have them cut your new arrows and attach the nocks. It is important to find your anchor spot and be consistent each time you draw an arrow. If a bow is set up correctly to you, when you draw it back you will hit what we call the wall. This is simply the cam maxing out giving the feeling that the bow has been fully drawn. Archery is all about practice and form. Good sights and a good fall away rest improve accuracy the rest is up to the shooter to hold form through the release of the arrow. Have them set up a kisser button which you use to know you are at your anchor spot, bow shop will show you. A lot of archers like to have the string lightly touch their nose and have their kisser button hit the corner of their mouth. It's all about consistent form repeated every time. Keep us up-dated on your progress.